1. Field of the Invention
The invention relates in general to motion estimation, and more particularly to 3-D recursive search motion estimation using statistic temporal prediction.
2. Description of the Related Art
Conventionally, through 3-D recursive search motion estimation including spatial prediction and temporal prediction, motion vectors for all blocks in a current frame can be obtained. Referring to FIG. 1, a schematic diagram illustrating temporal prediction used in the conventional 3-D recursive search motion estimation is shown. In FIG. 1, temporal prediction of a block 112 can be obtained by reference to motion vectors of the left-down block 104 and the right-down block 106 of a previous block 102 in a previous frame 100, which is location corresponding to the block 112.
However, the temporal prediction in FIG. 1 only refers to the motion vectors of the left-down and right-down blocks 104 and 106 of the previous block 112. Once the motion vectors of the left-down block 104 or the right-down block 106 has errors, the motion vector of the block 112 is very likely to have errors due to incorrect temporal prediction.
Besides, the temporal prediction in FIG. 1 also has to store motion vectors of all blocks in the previous frame 100, which in turn increases the memory cost. Therefore, a system and method for 3-D recursive search motion estimation, which includes accurate and cost-effective temporal prediction, is much demanded.